[12.x] Fix RateLimiter remaining() to handle negative maxAttempts values

[faisuc]

Fixes #58014.

PR #57851 changed RateLimiter::remaining() to use max(0, $maxAttempts - $attempts) to prevent negative values when attempts exceed the limit. This broke cases where $maxAttempts is negative.
Before PR #57851, remaining('key', -1) returned a negative number, so !remaining('key', -1) was false. After the change, it returned 0, so !remaining('key', -1) became true, which is incorrect.
This fix checks if $maxAttempts >= 0 before applying the max() clamp. For negative values, it returns -1 to indicate unlimited attempts, restoring the previous behavior while keeping the fix for non-negative values.
The change preserves PR #57851's behavior for normal cases and restores the ability to disable rate limiting with negative values.